During a fast, your body generates its own energy by burning stored resources made from excess fats, carbohydrates and sugars to produce energy. The liver is the most significant organ in this economical process; it converts the fats into chemicals called ketone bodies which are three water-soluble compounds that are then used as a source for energy.
Detoxification is one of the most important benefits of fasting. A regular body process, detoxification occurs as the colon, liver, kidney, lungs, lymph glands and skin eliminate or neutralise toxins. This process speeds up during fasting as the body breaks down fats. Chemicals and toxins absorbed from food and the environment are stored in fat reserves and released during fasting.
Fasting is also a healing for the mind, body and soul in more ways than one. At a physical level, energy and resources are diverted from the digestive system (which is constantly in overuse as we graze on food) to the immune system and metabolic processes allowing the body to heal, rebuild and replenish itself. Medical studies show that during a fast, abnormal tissue growths such as tumours become starved for nutrients and are hence more susceptible to being broken down and removed from the body. Fasting allows the body to tap its resources to their fullest potential and focus on rebuilding from a microscopic level as DNA and RNA genetic controls become more efficient in transcribing the proteins and tissues the body needs. This revamped protein synthesis results in healthier cells, tissues and organs.
Other changes in the body during a fast include a slight decrease in core body temperature due to a decline in metabolic rate and general bodily functions. Blood sugar levels also drop as the body uses the reservoir of glycogen in the liver and the base metabolic rate (BMR) is reduced in order to conserve energy. The digestive system, which is very often overloaded, and ceaselessly put to work, also cleanses itself for more efficient digestion and nutrient absorption. The lining of the stomach and intestines are allowed to restore glands and muscle, and remove waste matter. Other processes that sustain the foundational infrastructure of the body are increased during fasting, for example hormone production is increased as well as the release of anti-aging growth hormones.
Fasting leads to slower metabolism and higher cortisol - which is a recipe for high stress.
Fasting Damages Your Muscles
Your body will feed off your body; cortisol will leach amino acids from your own muscles so that it has sugar to consume. This sugar will go to your brain, kidneys and RBCs . While fat is useful to the brain, it likes sugar, and red blood cells.
Fasting Damages your Digestion
"Fasting creates an abnormal physiological state. Those who adopt fasting as a means of detoxification ultimately end up developing gastrointestinal problems," says Dr S K Thakur, senior consultant, gastroenterologist, Moolchand Medcity.
Your body has peak times for secretion of digestive enzymes (at breakfast, lunch and dinner) are "In the absence of food, these enzymes keep circulating within and damage the lining of the digestive tract. This leads to acid reflux, gastritis problems and even ulcer," says Dr Thakur.
The gall bladder's bile contents are used for digestion when you eat. When bile doesn't have food to act upon, it gets stored inside your gall bladder.
"In the absence of food, this bile keeps accumulating inside the gall bladder. Gradually it can turn into sludge, leading to the formation of stones," cautions Dr Thakur.
Fasting Kills Your Immunity
When you don't eat, your intestinal tract (responsible for over 70% of your antibodies) will stops working for your immunity. In the absence of antibodies, bacteria, toxins, and viruses suddenly have a easier time staying alive inside your gut. When the raw material necessary for a intestinal tract (sufficient calories, proteins, and certain vitamins and minerals) is missing, your immunity is shot.
Which is why people die from long term fasting.
Fasting Won't Help Weight Loss
What you're losing is actually water weight (the water content in food also counts!). And the weight lost due to ketosis comes back - you'll crave high fat foods after a fast. You might even think you deserve some off-time from your diet and forget about exercising and eating right. Eating normally will bring back your hunger, but the slower metabolism, combined with an increased appetite will make you fat.
Long term ketosis kills - your body is converting protein into sugar, and this protein comes from the liver, spleen and muscles. Soon, your blood glucose level falls, leading to electrolytes imbalance occurs - and then death.
Fasting Gives our Bodies a Rest
Every second, hormones are at play, enzymes are swimming about, and your energy cells are storing energy. All this needs food. No food will put a strain on your body's vital processes - not 'rest' it.
The Fasting Detox Myth
The most vocalized, yet the least scientifically understood myth, a vague and faulty understanding of the body purging toxins when we fast is used to justify fasting. This belief doesn't take into account the processed nature of our food, and the stringent food safety regulations.
In fact. fasting puts stain on our liver and kidneys which are continuously working to "detox". If you are healthy, your body is pretty much toxin free already. And the above-mentioned ketones, along with increased nitrogen products will put more strain on your body. The only cleanse you can have is eating healthy food and a regular bowel movements.